In addition to other fields of application, tube pumps are i.a. used in extracorporeal blood treatment such as dialysis to convey a fluid, in this case blood. Spring-loaded rollers which are to limit the maximum pressure of the pump—which additionally depends on the pump tube diameter—are state of the art. With increasing mechanical complexity of the pump rotor, the number of possible sources of failure usually increases, this is also true for tube pumps. Therefore, it is useful to check the proper functioning of the rotor. In WO 2010/020380 A1, a method is disclosed for monitoring the pump rotor during pump operation. Thereby, pressure gradients which are caused by the roller which is in mesh in the moment of observation are raised and compared with pressure gradients of other rollers. If deviations occur, a defect of the pump motor is concluded. A defect similarly affecting both (in the sense of all) rollers cannot, inherent to the functional principle, be detected. This is not the case using certain embodiments of the method according to the present invention. In such embodiments, defects and failures which lead to the improper performance of all involved displacers or the displacers which are checked for their functioning can advantageously also be detected. Such a failure can be—for example because of its tube diameter or material—the use of a tube which is not suitable for the concrete application. Further, such a failure can exist for example because of striations in the inner layer of the pump tube which can be caused through production faults. Because of the absolute measurements which are possible according to the present invention, which can be performed for each displacer independently from one another, a damage which can affect all displacers in the same way can be advantageously recognized.
As such one object of the present invention is to propose a further method for verification of the function of the displacers of a tube pump. In addition, suitable apparatuses, a suitable digital storage medium, a suitable computer program product and a suitable computer program are to be specified.
Thus, according to the present invention a method for detecting a permeability or patency of a section of an extracorporeal tube which is inserted in a tube pump and/or for verifying an occlusion effect of displacers of the tube pump on the tube, i.e. the flow rate in the longitudinal direction of the tube is proposed. The method according to the present invention encompasses the meshing of a displacer of the tube pump with the section of the tube in such a manner that the displacer reduces the permeability or patency of the lumen of the section for a fluid and/or the cross-sectional area of the section of the lumen. The method further encompasses building up, setting or effecting a first pressure or the effecting a first pressure change inside the tube on a first side of the section and/or the meshed displacer. Furthermore, the method according to the present invention encompasses measuring a second pressure or a second pressure change and/or evaluating a second pressure already measured or a second pressure change already measured respectively on a second side of the section and/or of the meshed displacer.